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v12 radiosurgery

James M Taylor, Emory R McTyre, Stephen B Tatter, Adrian W Laxton, Michael T Munley, Michael D Chan, Christina K Cramer
BACKGROUND/AIMS: Brain metastases from bladder cancer are rare and published outcomes data are sparse. To date, no institutions have reported a series of patients with brain metastases from bladder cancer treated with stereotactic radiosurgery (SRS). Our aim was to identify patients with brain metastases from bladder primaries treated with SRS with or without surgical resection and report the clinical outcomes. METHODS: Patients meeting eligibility criteria at our institution between 2000 and 2017 were included...
April 26, 2018: Stereotactic and Functional Neurosurgery
Qian Du, Chi Zhang, Xiaofeng Zhu, Xiaoying Liang, Chi Zhang, Vivek Verma, Kenneth Follet, Shuo Wang, Qiyong Fan, Rongtao Ma, Sumin Zhou, Dandan Zheng
OBJECTIVES: To apply advanced statistical and computational methodology in evaluating the impact of anatomical and technical variables on normal tissue dosimetry of trigeminal neuralgia (TN) stereotactic radiosurgery (SRS). METHODS: Forty patients treated with LINAC-based TN SRS with 90 Gy maximum dose were randomly selected for the study. Parameters extracted from the treatment plans for the study included three dosimetric output variables: the maximum dose to the brainstem (BSmax), the volume of brainstem that received at least 10 Gy (V10BS), and the volume of normal brain that received at least 12 Gy (V12)...
May 2018: Medical Physics
Ruggero Ruggieri, Stefania Naccarato, Rosario Mazzola, Francesco Ricchetti, Stefanie Corradini, Alba Fiorentino, Filippo Alongi
BACKGROUND: Linac-based stereotactic radiosurgery or fractionated stereotactic radiotherapy (SRS/FSRT) of multiple brain lesions using volumetric modulated arc therapy (VMAT) is typically performed by a multiple-isocenter approach, i.e. one isocenter per lesion, which is time-demanding for the need of independent setup verifications of each isocenter. Here, we present our initial experience with a new dedicated mono-isocenter technique with multiple non-coplanar arcs (HyperArc™, Varian Inc...
March 5, 2018: Radiation Oncology
Muhammad M Fareed, Ahmed Eldib, Stephanie E Weiss, Shelly B Hayes, Jinsheng Li, Charlie C-M Ma
To compare the dosimetric parameters of a novel rotating gamma ray system (RGS) with well-established CyberKnife system (CK) for treating malignant brain lesions. RGS has a treatment head of 16 cobalt-60 sources focused to the isocenter, which can rotate 360° on the ring gantry and swing 35° in the superior direction. We compared several dosimetric parameters in 10 patients undergoing brain stereotactic radiosurgery including plan normalization, number of beams and nodes for CK and shots for RGS, collimators used, estimated treatment time, D 2 cm and conformity index (CI) among two modalities...
February 2, 2018: Physics in Medicine and Biology
Charlotte Rivers, Marissa Tranquilli, Shefalika Prasad, Evan Winograd, Robert J Plunkett, Robert A Fenstermaker, Andrew J Fabiano, Matthew B Podgorsak, Dheerendra Prasad
PURPOSE/OBJECTIVES: The purpose of this study was to evaluate the effect of the number of brain lesions for which stereotactic radiosurgery (SRS) was performed on the dose volume relationships in normal brain. MATERIALS AND METHODS: Brain tissue was segmented using the patient's pre-SRS MRI. For each plan, the following data points were recorded: total brain volume, number of lesions treated, volume of brain receiving 8 Gy (V8), V10, V12, and V15. RESULTS: A total of 225 Gamma Knife® treatments were included in this retrospective analysis...
October 11, 2017: Stereotactic and Functional Neurosurgery
Alexandra Hellerbach, Klaus Luyken, Mauritius Hoevels, Andreas Gierich, Daniel Rueß, Wolfgang W Baus, Martin Kocher, Maximilian I Ruge, Harald Treuer
BACKGROUND: As irradiated brain volume at 12 Gy (V12) is a predictor for radionecrosis, the purpose of the study was to develop a model for Cyberknife (CK) plans that is able to predict the lowest achievable V12 at a given tumor size and prescription dose (PD), and to suggest a new quality index regarding V12 for optimizing the treatment planning of brain metastases. METHOD: In our model V12 was approximated as a spherical shell around the tumor volume. The radial distance between tumor surface and the 12 Gy isodose line was calculated using an approximation of the mean dose gradient in that area...
August 17, 2017: Radiation Oncology
Mustafa Aziz Hatiboglu, Kerime Akdur
BACKGROUND: Treatment of patients with multiple brain metastases has shifted to stereotactic radiosurgery, withholding whole-brain (WB) radiation therapy. However, radiation toxicity to the brain is a concern when treating multiple brain lesions with single-fraction stereotactic radiosurgery. OBJECTIVE: The purpose of this study was to determine the changes in brain radiation doses when treating various numbers of targets and lesion volumes. METHODS: We simulated different treatment plans with different combinations of varying tumor volumes including 0...
2017: Stereotactic and Functional Neurosurgery
Byron Wilson, Karl Otto, Ermias Gete
INTRODUCTION: We present a Trajectory-based Volumetric Modulated Arc Therapy (TVMAT) technique for Stereotactic Radiosurgery (SRS) that takes advantage of a modern linacs ability to modulate dose rate and move the couch dynamically. In addition, we investigate the quality of the developed TVMAT method and the dosimetric accuracy of the technique. METHODS: The main feature of the TVMAT technique is a standard beam trajectory formed by dynamic motion of the treatment couch and the linac gantry...
January 2017: Medical Physics
T Lamberton, J Slater, A Wroe
PURPOSE: Stereotactic radiosurgery is an effective and noninvasive treatment for intracranial lesions that uses highly focused radiation beams in a single treatment fraction. The purpose of this study is to investigate the dosimetric differences between the treatment brain metastasis with a proton beam vs. intensity modulated radiation therapy (IMRT). METHODS: Ten separate brain metastasis targets where chosen and treatment plans were created for each, using three different strategies: custom proton beam shaping devices, standardized proton beam shaping devices, and IMRT...
June 2016: Medical Physics
J Maurer, B Sintay, M Manning, D Wiant, H Liu
PURPOSE: This study evaluates a novel algorithm that can be used with any treatment planning system for simple and rapid generation of stereotactic radiosurgery (SRS) plans for treating multiple brain metastases using a single isocenter dynamic conformal arc (DCA) approach. This technique is compared with a single isocenter volumetric modulated arc therapy (VMAT) technique in terms of delivery time, conformity, low dose spread and delivery accuracy. METHODS: Five patients, with a total of 37 (5 - 11) targets were planned using a previously published method for generating optimal VMAT plans and using the proposed DCA algorithm...
June 2016: Medical Physics
Y Chen, C Li, C Yang
PURPOSE: Safe treatment of the maximum tolerable brain metastases with GK in single patient-clinical findings METHODS: A patient diagnosed with stage IV NSCLC has received 6 courses of Gamma Knife radiosurgery (GKRS) treatments. The plans were generated with GammaPlan (version 10.1.1), six courses of treatment were administered in 2.5 years. A total of 53 metastases were treated with retreatment foci (n = 5) and planned on newly identified lesions (n = 48). Individual prescription dose varied from 12 Gy to 24 Gy...
June 2016: Medical Physics
C Yeboah, M Ruschin, Y Lee, A Sarfehnia, B Chugh, S Myrehaug, M Tsao, H Soliman, A Sahgal
PURPOSE: To assess the feasibility of designing clinically-acceptable stereotactic radiosurgery (SRS) plans utilizing linac-based cone collimators for patients presenting with acoustic neuroma. METHODS: Five acoustic neuroma patients with gross tumour volumes (GTVs) of sizes from 1.3 to 2.7 cc were studied. The cranial-caudal extent of the GTVs range from 1.1 to 1.7 cm whereas the largest cross-sectional extent of the lesions varied from 2.0 to 2.4 cm. No PTV margin was added...
June 2016: Medical Physics
J Baker, J Gibb, S Ailawadi, A Hsia, J Han, J Kim, Z Xu, S Ryu
PURPOSE: The volume of normal brain tissue exposed to doses above 12 Gy (V12) strongly predicts the risk of radionecrosis. A negative margin MLC aperture results in fields smaller than the PTV. The aim of this study is to investigate the relationship between V12 and the negative margin MLC while keeping adequate PTV coverage with proper dose normalization. METHODS: Spherical PTVs were contoured with a center of mass in the frontal and left temporal lobe ranging in size from 1 cm to 4 cm in diameter...
June 2016: Medical Physics
D Levin, E Shekel, D Epstein, R Spiegelmann, R Pfeffer
PURPOSE: To evaluate a new, automated brain metastases planning software designed to treat up to ten brain metastases simultaneously. METHODS: We treated 61 patients with multiple brain metastases using the Elements software by BrainLab (Munich, Germany). Patients had between 2-10 metastases ranging from 0.01-8.64 cc. Dose prescription was 18-24 Gy. Plans use up to 5 non-coplanar arcs with a single isocenter at the metastases' center of mass. The high degree of automation shortens the planning time to 15-20 minutes per patient...
June 2016: Medical Physics
Ganesh Narayanasamy, Sotirios Stathakis, Alonso N Gutierrez, Evangelos Pappas, Richard Crownover, John R Floyd, Niko Papanikolaou
BACKGROUND: In this treatment planning study, we compare the plan quality and delivery parameters for the treatment of multiple brain metastases using 2 monoisocentric techniques: the Multiple Metastases Element from Brainlab and the RapidArc volumetric-modulated arc therapy from Varian Medical Systems. METHODS: Eight patients who were treated in our institution for multiple metastases (3-7 lesions) were replanned with Multiple Metastases Element using noncoplanar dynamic conformal arcs...
October 2017: Technology in Cancer Research & Treatment
Juan F Calvo-Ortega, David Delgado, Sandra Moragues, Miquel Pozo, Joan Casals
AIMS: To dosimetrically compare the fixed gantry intensity modulated radiosurgery (IMRS) with dynamic conformal arc radiosurgery (DCARS) for cranial lesions. This study investigates whether IMRS can be an adequate dosimetric alternative to DCARS for cranial stereotactic radiosurgery (SRS). SUBJECTS AND METHODS: Forty-five SRS procedures for solitary brain metastasis (range: 0.44-29.18 cm 3) performed at our institution were selected for this study. Two plans were generated per patient: One IMRS plan using a multileaf collimation (MLC) of 5 mm, and one DCARS plan designed with a 3 mm micro-MLC...
April 2016: Journal of Cancer Research and Therapeutics
Rafael Garcia, Kita Sallabanda, Iciar Santa-Olalla, Jose Luis Lopez Guerra, Lijia Avilés, Morena Sallabanda, Eleonor Rivin, José Samblás
Modern technologies allow the delivery of high radiation doses to intramedullary spinal cord metastases while lowering the dose to the neighboring organs at risk. Whether this dosimetric advantage translates into clinical benefit is not well known. This study evaluates the acute and late toxicity outcomes in a patient treated with robotic radiosurgery for an intramedullary spinal cord metastasis. A 50-year-old woman diagnosed in May 2006 with invasive ductal carcinoma of the right breast T2N3M1 (two liver metastases) received chemotherapy with a complete response...
2016: Curēus
Thierry Gevaert, Femke Steenbeke, Luca Pellegri, Benedikt Engels, Nicolas Christian, Marie-Thérèse Hoornaert, Dirk Verellen, Carine Mitine, Mark De Ridder
PURPOSE: To investigate the feasibility of a novel dedicated treatment planning solution, to automatically target multiple brain metastases with a single isocenter and multiple inversely-optimized dynamic conformal arcs (DCA), and to benchmark it against the well-established multiple isocenter DCA (MIDCA) and volumetric modulated arc therapy (VMAT) approaches. MATERIAL AND METHODS: Ten previously treated patients were randomly selected, each representing a variable number of lesions ranging between 1 to 8...
February 2, 2016: Radiation Oncology
Tianfang Li, Cihat Ozhasoglu, Steven Burton, John Flickinger, Dwight E Heron, M Saiful Huq
For targets with substantial volume, collimators of relatively large size are usually selected to minimize the treatment time in robotic radiosurgery. Their large penumbrae may adversely affect the dose gradient around the target. In this study, we implement and evaluate an inner-shell planning method to increase the dose gradient and reduce dose to normal tissues. Ten patients previously treated with CyberKnife M6 system were randomly selected with the only criterion being that PTV be larger than 2 cm(3). A new plan was generated for each patient in which the PTV was split into two regions: a 5 mm inner shell and a core, and a 7...
November 8, 2015: Journal of Applied Clinical Medical Physics
Andrew Woerner, John C Roeske, Matthew M Harkenrider, John Fan, Bulent Aydogan, Matthew Koshy, Robert Laureckas, Faisal Vali, Maria Campana, Murat Surucu
PURPOSE: A multi-institutional planning study was performed to evaluate the frequency that current guidelines established by Radiation Therapy Oncology Group (RTOG) protocols and other literature for lung stereotactic body radiotherapy (SBRT) treatments are followed. METHODS: A total of 300 patients receiving lung SBRT treatments in four different institutions were retrospectively reviewed. The treatments were delivered using Linac based SBRT (160 patients) or image guided robotic radiosurgery (140)...
August 2015: Medical Physics
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